Control system for movable storage units

ABSTRACT

A movable storage system includes at least two movable storage units, a brush-less motor accommodated in each of the units for moving the units in movement directions, each of the motors comprising a plurality of stators and a rotor, and each of the motors including a sensor. Each sensor detects an angular position and a rotational speed of a respective rotor of each motor using the magnetic poles of the rotor. Each sensor outputs an angular position signal representing the angular position and a rotational speed signal representing the rotational speed of the rotor. A motor control is associated and in communication with each motor and sensor, which is operable for controlling the motor. The controls are adapted to receive the position and speed signals of each sensor with each control having a signal-outputting terminal to provide a command signal output to its respective motor. In addition, the system includes a master control that is in communication with the motor controls, which obtains the speed and angular position signals from each of the motor controls. Further, each unit includes a communications board, which allows exchange of information between the motor controls and the master control, which includes the speed and angular position signals, wherein the master control commands a respective unit that needs to be moved to move or stop in a movement direction by sending a control signal to the motor control of the respective unit. The motor control compares the speed and the position signals with the control signal to provide a motor control signal to the motor of the respective unit to control electric current supplied to the stators of the motor of the respective unit to control rotational speed and angular position of the rotor of that motor.

TECHNICAL FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to movable storage systems and, more particularly, to a control system for a movable storage system with a plurality of movable storage units.

Movable storage units are used in areas where the storage space requirements exceeds the available amount of the storage space requirements or are used simply to maximize the available storage space for a given area. The storage units typically take the form of shelves, racks or the like, which are arranged adjacent one another and configured to move relative to one another to open and close the space between the units to create an aisle between one or more adjacent units. Some systems include two fixed end units that are spaced apart from one another with one or more intermediate movable units disposed between the end units. The distance between the fixed end units is sized to accommodate the movable units plus one or more aisles. As the movable units between the fixed units are moved, the space or gap between the movable units can be adjusted to create one or more aisles and, further, to shift the aisle or aisles where access to the individual unit or units is needed.

SUMMARY OF THE INVENTION

In one form of the invention, a storage system includes at least one movable storage unit and a control system. The movable storage unit includes a motor, which is controlled by the control system. The control system is in communication with the motor and controls and determines the linear movement of the storage unit based on rotation of the rotational position of the motor's rotor.

In another form of the invention, a movable storage system includes at least two movable storage units, which are movable in at least two movement directions, a brush-less motor accommodated in each of the movable storage units for moving the units in the movement directions, and a brush-less motor control associated and in communication with each of the brush-less motors. The brush-less motors include a plurality of stators, a rotor, which includes magnetic poles, and a sensor. The sensors detect the angular position and rotational speed of the rotors using the magnetic poles of the rotors. In addition, each of the sensors outputs an angular position signal representing the angular position and a rotational speed signal representing the rotational speed of the respective rotor. The motor controls are operable for controlling the brush-less motors and are adapted to receive the position signals and the speed signals of each respective sensor of the brush-less motors. Each of the motor controls has a signal-outputting terminal to provide a command signal output to the respective brush-less motor. A master control is in communication with the brush-less motor controls, which obtains the speed signals and the angular position signals from the brush-less motor controls. Each of the movable storage units includes a communications board that allows exchange of information between the brush-less motor controls and the master control. The information, for example, may include the speed signals and the angular position signals. The master control commands one or more of the movable storage unit that needs to be moved to move or stop in the movement direction by sending a control signal to the brush-less motor control of the respective movable storage unit, with the brush-less motor control comparing the speed signal and the position signal with the control signal to provide a motor control signal to the motor of the respective movable storage unit to control the electric current supplied to the stators of the motor of the respective movable storage unit to control rotational speed and angular position of the rotor of the motor of the respective movable storage unit in the movement direction.

In one aspect, the sensors are Hall-effect sensors, which produce the position and speed signals. Optionally, the position signals and the speed signals generated by the Hall effect sensors are processed into a set of pulses input to the motor controls, which controls the electric current supplied to the stators on the motors to control speed and position of the rotors.

In another aspect, the movable storage system may also include a sweep control module with an infrared photo eye, which detects objects in an aisle of the movable storage system. The sweep control module is configured to prevent the movable storage units from running into an object in the aisle; therefore, when the sweep control module sends an aisle object detection signal to the master control, the master control sends a stop or start signal to a motor control of the appropriate movable storage unit or units.

According to yet another aspect, the movable storage system may include a light carpet system, which provides an infrared beam to scan a floor of the movable storage system. The infrared beam scans the floor of the movable storage system to detect the presence of an object on the floor of the movable storage system. When the beam detects the presence of an object, the light carpet system sends a floor object detection signal to the master control, which in turn sends a stop or start signal to the motor control of the appropriate storage unit.

According to another form of the invention, a movable storage system includes at least two movable storage units that are movable in at least two movement directions, a motor associated with and selectively moving each of the movable storage units for moving the units in the movement directions, and a control system. Each of the motors comprises a rotor and a sensor for detecting the angular position and rotational speed of the rotor, which is in communication with the control system. The control system receives information about the angular position and rotational speed of the rotors and controls the linear position of the movable storage units based on the angular position and rotational speed of the rotors.

In one aspect, the motors comprise brush-less motors. For example, the brush-less motors preferably include a sensor, a rotor with a plurality of magnetic poles, and a plurality of stators each including an electromagnet. Each of the sensors detects an angular position and a rotational speed of a respective rotor using the magnetic poles of the respective rotor and outputs an angular position signal representing the angular position and a rotational speed signal representing the rotational speed of the respective rotor to the control system.

In another aspect, the control system includes a master control and a carriage control for each motor, with the master control in communication with each of the carriage controls. For example, the carriage controls receive the angular position signals and the rotational speed signals from the sensors and, further, communicates at least the content of the angular position signals and the rotational speed signals to the master control. When an open aisle request is received by the master control, the master control determines which respective movable storage units need to be moved, the direction in which the respective movable storage units need to moved, and the left or right distance the respective movable storage units need to be moved, and generates a command signal to each carriage control of the respective movable units that need to be moved.

Accordingly, the present invention provides enhanced control and greater accuracy in the movement of storage units.

These and other objects, features and advantages of the present invention will be more readily apparent from the detailed description of the preferred embodiments set forth below, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one configuration of a movable storage system of the present invention;

FIG. 2 is a flow chart illustrating the basic operation of the system of FIG. 1;

FIG. 3 is a block diagram of the basic control system of the storage system of FIG. 1;

FIG. 4 is a schematic of the motor control of the control system;

FIG. 5 is a schematic of the carriage control of the control system;

FIG. 6 is a schematic of the master control of the control system;

FIG. 7 is a schematic of the sweep controller of the control system;

FIG. 8 is a schematic of the input/output module of the control system;

FIG. 9 is a schematic of the light carpet of the control system;

FIG. 10 is a schematic of the master display of the control system;

FIG. 11 is a schematic of the carriage control bezel of the control system; and

FIG. 12 is a schematic of the aisle lighting control of the control system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, the numeral 10 generally designates a storage system of the present invention. Storage system 10 incorporates movable storage units 12 that are arranged adjacent to one another and optionally between two fixed storage units 14 and are arranged so that their open facing sides 12 a, 12 b are facing each other or facing the end units. Movable storage units 12 are movable along an axis A extending between fixed storage units 14 and are selectively moved in either a left movement direction or a right movement direction to increase or decrease the space between the movable units and/or between the movable units and the fixed units to form an aisle between at least one set of adjacent storage units. The respective positions of movable storage units 12 are controlled by a control system 16 (FIG. 3), which is adapted to provide greater accuracy in the movement of the movable storage units and, further, greater control over the movement of the movable storage units to avoid a run-away unit. As will be more fully described below, control system 16 achieves the greater accuracy and control by monitoring and converting the rotary position of the motors' rotors that drive the movable storage units into linear movement of one or more movable storage units depending on where an aisle is desired.

Fixed storage units 14 are mounted in fixed position to the floor or other supporting structure of a building and are spaced apart from one another to accommodate the movable storage units intermediate the fixed units and at least one aisle. As will be more fully appreciated from the description that follows, control system 16 controls the movable storage units 12 in a manner to permit the movable storage units to be arranged between the fixed units such that the total gap between all of the storage units equals about one aisle width to thereby maximize the storage space for that given area of the building. This can be achieved at least in part by the precise positioning of the movable storage units and by the speed at which the positions of the movable units can be adjusted. However, it should be understood that the space between the storage units may be increased to accommodate more than one aisle.

In the illustrated embodiment, system 10 includes four intermediate movable storage units 12 disposed between end units 14. Movable units 12 are mounted on wheels 18 that are guided along tracks 20, which are mounted to the floor or the other supporting structure of the building. Each movable unit 12 is equipped with a drive motor 22, which is in communication via power and control wiring to control system 16 and which includes internal sensors to detect the rotation of the motor's rotor to control the movement of the movable storage units.

Motors 22 preferably comprise brush-less motors, which are conventional devices as, for example, of the type available from Bodine. In general, brush-less motors include a rotor with magnetic poles, a plurality of stators, with each stator consisting of an electromagnet, and a plurality of magnetic-pole sensors for sensing the angular position of the rotor's magnetic poles. Hall-ICs are widely used as such sensors. Each of the sensors is provided in the form of a single package in which a Hall-effect semiconductor, an amplifier for amplifying a weak signal output from the semiconductor, a Schmidt-trigger circuit converting the amplified signal into a square wave, a power regulator circuit and a temperature compensation circuit. The motor works by turning on or off the electromagnets in a manner to make the rotor turn. Control system 16 keeps track of the number of electromagnets turned on to determine the position of the rotors.

Control system 16 includes a master control 24 and a carriage control 26 for each movable storage unit 12, which are in communication with the master control 24. The control signals output from carriage controller 26 include those signals that turn on or off the motor 22 of the respective movable storage unit, change rotational speed of the motor, and/or switch over the direction of its rotation from forward to reverse, or vice versa. The magnetic-pole sensor successively receives from the Hall-effect semiconductor a series of signals (i.e., polar signals) representing the angular position (rotational phase) of the poles-carried by the rotors to thereby detect the angular position and rotational speed of the rotor. Each sensor outputs an angular position signal representing the angular position and a rotational speed signal representing the rotational speed of the respective rotor. The motor control (28 a), noted below, of each carriage controller 26 is in communication with the brush-less motor of its respective movable storage unit and its sensor and, further, is configured to control the brush-less motor to move or stop the respective storage unit. Optionally, braking can be achieved by reversing the direction of the motor. Alternately, braking can be achieved by an external brake, in which case motor control 28 is configured to interface with the external brake to control the movement of the storage unit.

The motor controls are adapted to receive the respective position signals and the speed signals of each respective sensor of the brush-less motors and include signal-outputting terminals to provide command signals to their respective brush-less motors. The signals from the sensors are converted into pulse waves by carriage controls 26, before they are supplied to the master control 24. Master control 24, which is in communication with the motor controls, receives the speed signal and the angular position signal from each of the carriage controls so that positions of the respective movable storage units may be monitored so that when a request to open an aisle is made, master control 24 can determine which movable units need to be moved, in which direction they need to moved, and how far they need to be moved, as noted below. In addition, optionally breaking can be achieved by shorting the wirings of the stators.

In addition, control system 16 includes a carriage control bezel or input device 30 (FIGS. 2, 3, and 11), which allows an operator to request an aisle to open. For example, input device 30 may include a button or a key pad with one or one or more keys or buttons, with at least one key for each aisle. The key pad may include additional buttons or keys for providing other or additional input, such as access or pass code numbers. As would be understood from the foregoing, each movable storage unit has associated therewith two possible aisle locations—one to the left of the movable storage unit and one to the right, unless the movable storage unit is an end movable unit in which case the unit may only need one aisle location. For example, each input may include a button to signal that a request is being made for an aisle to open to the left of the movable unit and a second button to signal that a request is being made for an aisle to open to the right of the movable unit. Alternately, a three position switch or button may be provided.

Referring to FIG. 2, when an operator requests an aisle to open by inputting the request into input 30, carriage control 26 receives a request signal from input 30 and carriage control 26 communicates the request signal to master control 24. When master control 24 receives the request signal from carriage control 26, master control 24 determines the locations of each movable unit and determines which of the movable units 12 need to be moved and, further, where they have to be moved. Master control 24 then determines the left and right distances or limits that the movable units need to be moved to open the requested aisle. Master control 24 then generates a signal to each carriage control of the respective movable units that have to be moved with the left or right limits. The carriage control 26 then converts the linear signal into a rotary signal to power the respective motor so that the motors' rotors only rotate over the prescribed angular range to thereby control and accurately position the respective movable units. When converting the linear signal, the motor control compares the speed signal and the position signal with the control signal from the master control to provide a motor control signal to the motor of the respective movable storage unit to control electric current supplied to the stators of the motor to control the rotational speed and angular position of the rotor and thereby to control the movement of that particular movable storage unit in the movement direction.

Each carriage control 26 includes a motor control 28 a, as noted above and shown in the schematic illustrated in FIG. 4, and a communications board 28 b, such as shown in FIG. 5, which manages information in the main control loop 32 of the main control 24 as well as the local control loop 34 of each movable unit. Alternately, the communications board may be integrated into the motor control. Communications boards 28 b allow exchange of information between the motor controls 28 a and the master control 24, such as the speed signals and the angular position signals. For example, master control 24 may provide directional commands of rotate clockwise or rotate counterclockwise for the motor controls to change direction of movement for each unit and/or provide speed variation signals to the motors.

As best seen in FIG. 3, each local control loop 34 may include an input/output (I/O) module 36, such as shown in FIG. 8, with one or more switches, such as dip switches, that adjust its identification and function. For example, I/O module 36 may be set to turn lights, such as aisle lights 38 (FIG. 12), on or off or may be set to monitor a carriage safety device 40 (FIG. 8). In addition, master control 24 may control the manner of operation of a motor according to a command from an input/output module. Further, I/O module may control an identification address of each motor control.

In addition, each local control loop 34 may include a sweep controller or control module 42, such as illustrated in FIG. 7, which operates one or more infrared photo eyes 44 to detect an object in the path of the movable storage unit and prevent the storage unit from running over an object. The sweep control module sends an aisle object detection signal to the master control, which then sends appropriate stop or start signals to the appropriate motor controls. The sweep controller and the I/O module of each local control loop are optionally daisy chained together.

In addition, control system 16 may incorporate a light carpet system 46, such as described in U.S. Pat. No. 5,408,089 and shown in FIG. 9, which is hereby incorporated by reference herein in its entirety, which consists of infrared photo eyes that scan the whole floor area of the storage system. The light carpet system may be incorporated anywhere in the main control loop 32 and communicates with main control 24 to tell the system when to stop or go. The infrared photo eyes generate an infrared beam that scans the floor of the movable storage system and detects the presence of objects on the floor of the movable storage system. When the beam or “light carpet” detects an object on the floor, the light carpet system sends a floor object detection signal to the master control, which then sends appropriate stop or start signals to the appropriate motor controls.

In order to display system information and/or status, control system optional includes a master display 48, such as shown in FIG. 10, which may be configured to display the system's status information, motor control status, motor status, sensor status, information about the items stored in the system, and other information. A suitable display includes an LCD display or the like. Master display 48 is located in the main control loop 32 and in communication with master control 24, which may be configured to update information for display on master display 48.

As would be understood, because the present system does not use plungers, limit switches or proximity switches to control the movement of the movable storage units, which are used in conventional movable storage systems, the present control system can achieve greater accuracy in moving the storage units and, further, can eliminate the delays inherent in such systems and, therefore, can move them more quickly.

As will be readily appreciated, numerous variations of and additions to the features discussed above can be utilized without departing from the present invention. For example, the storage system may include more or less movable storage units. Further, the end units may be movable as well. For example, the storage system 10 may incorporate a detection system and logic described in U.S. Pat. No. 5,408,089, which is incorporated herein in its entirety, to check for the presence or absence of objects or persons in the area between the storage units, as noted above. These and other variations and further modifications can be used in the present invention without departing from the scope of the invention. 

1. A movable storage system comprising: at least two movable storage units being movable in at least two movement directions; a brush-less motor accommodated in each of said movable storage units for moving said units in the movement directions, each of said brush-less motors comprising a plurality of stators and a rotor, said rotor having magnetic poles; each of said brush-less motors including a sensor, each of said sensors detecting an angular position and a rotational speed of a respective rotor using said magnetic poles of said respective rotor, each of said sensors outputting an angular position signal representing the angular position and a rotational speed signal representing the rotational speed of said respective rotor; a brush-less motor control associated and in communication with each respective brush-less motor of said brush-less motors and said sensor of said respective brush-less motor, said motor controls operable for controlling said brush-less motors, said motor controls adapted to receive said position signals and said speed signals of each respective sensor of said brush-less motors, each of said motor controls having a signal-outputting terminal to provide a command signal output to said respective brush-less motor; a master control in communication with said brush-less motor controls, said master control obtaining said speed signal and said angular position signal from each of said brush-less motor controls; each of said movable storage units including a communications board, said board allowing exchange of information between said brush-less motor controls and said master control, said information including said speed signals and said angular position signals; and wherein said master control commands a respective movable storage unit that needs to be moved to move or stop in said movement direction by sending a control signal to said brush-less motor control of said respective movable storage unit, said brush-less motor control comparing said speed signal and said position signal with said control signal to provide a motor control signal to said motor of said respective movable storage unit to control electric current supplied to said stators of said motor of said respective movable storage unit to control rotational speed and angular position of said rotor of said motor of said respective movable storage unit in the movement direction.
 2. The movable storage system of claim 1, wherein said sensors are Hall-effect sensors, said Hall-effect sensors producing said position and speed signals.
 3. The movable storage system as defined in claim 2, wherein said position signals and said speed signals generated by said Hall effect sensors are processed into a set of pulses input to said motor controls, said motor controls controlling electric current supplied to said stators on said motors to control speed and position of said rotors.
 4. The movable storage system of claim 3 further comprising a sweep control module providing an infrared photo eye, said photo eye detecting objects in an aisle of the movable storage system, said sweep control module configured to prevent said movable storage units from running into an object in the aisle; and wherein said sweep control module sends an aisle object detection signal to said master control, said master control sending a stop or start signal to a motor control of an appropriate movable storage unit.
 5. The movable storage system of claim 3 further comprising: a light carpet system providing an infrared beam to scan a floor of said movable storage system; said infrared beam scans the floor of the movable storage system and detects the presence of an object on the floor of the movable storage system; wherein said light carpet system sends a floor object detection signal to said master control when an object is detected; and said master control sending a stop or start signal to at least one of said motor controls when a floor object detection signal is received.
 6. The movable storage system of claim 5 further comprising: an input/output module connected to said motor control; and wherein said input/output module controls an identification address of said motor control.
 7. The movable storage system of claim 6, wherein one of said master control and said motor control controls operation of said motors according to a command from an input/output module.
 8. The movable storage system of claim 7, wherein said communications board allows communication between said motor control and said sensor.
 9. The movable storage system of claim 8, wherein one of said master control and said motor control provides directional commands of rotate clockwise or rotate counterclockwise for said motors to change direction of movement for each storage unit.
 10. The movable storage system of claim 9, wherein one of said master control and said motor control provides speed variation signals to said brush-less motors.
 11. The movable storage system of claim 10 further comprising a master display showing status of said motor controls.
 12. The movable storage system of claim 11 further comprising a master display showing status of said motors.
 13. The movable storage system of claim 12 further comprising a master display showing status of said sensors.
 14. The movable storage system of claim 1, wherein said communications boards are integrated into said motor controls.
 15. A movable storage system comprising: at least two movable storage units being movable in at least two movement directions; a motor associated with and selectively moving each of said movable storage units for moving said units in the movement directions, each of said motors comprising a rotor and a sensor for detecting the angular position and rotational speed of the rotor; and a control system in communication with said sensors, said control system controlling the linear position of said movable storage units based on said angular position and rotational speed of the rotors.
 16. The movable storage system according to claim 15, wherein said motors comprise brush-less motors.
 17. The movable storage system according to claim 16, wherein each of said brush-less motors includes a sensor, a rotor with a plurality of magnetic poles, and a plurality of stators each including an electromagnet, each of said sensors detecting an angular position and a rotational speed of a respective rotor using said magnetic poles of said respective rotor, each of said sensors outputting an angular position signal representing the angular position and a rotational speed signal representing the rotational speed of said respective rotor to said control system.
 18. The movable storage system according to claim 16, wherein said control system includes a master control and a carriage control for each motor, said master control in communication with each of said carriage controls.
 19. The movable storage system according to claim 18, wherein said carriage controls receives said angular position signals and said rotational speed signals from said sensors.
 20. The movable storage system according to claim 18, wherein said carriage controls communicate at least the content of said angular position signals and said rotational speed signals to said master control, and when an open aisle request is received by said master control, said master control determines which respective movable storage units need to be moved, the direction in which said respective movable storage units need to moved, and the left or right distance the respective movable storage units need to be moved, and said master control generating a command signal to each carriage control of the respective movable units that need to be moved.
 21. A method for controlling for a movable storage unit in a movable storage system having at least two movable storage units being movable in at least two movement directions, a motor with a rotor, a sensor accommodated in each of the motors, a control system in communication with the sensors and for selectively powering the motors, the method comprising the steps of: detecting the rotational position of the rotor of the motor of the respective unit by a sensor; sending rotor position data to the control system; surveying the status of the units with the control system based on the rotor position data; receiving an aisle open request from an input request source; determining which unit to move and in what direction to fulfill the aisle open request based on the rotor position data; determining the amount or rotation needed for the rotor of the respective motor to fulfill the aisle open request; and sending a drive signal to the motor of the respective unit to rotate the rotor the amount needed to fulfill the open aisle request.
 22. The method according to claim 21, further comprising: providing a brush-less motor with stators, a rotor, and a sensor in each of the movable storage unit, sensing the angular position and rotational speed of the rotor of each motor with their respective sensors; and communicating the angular position and rotational speed signals to the control system.
 23. The method of claim 22 further comprising: checking an aisle of the system for an object with a sweep control module; and stopping operation of a motor of an associated storage unit when an object is detected in the path of the associated storage unit by the sweep control module.
 24. The method of claim 23 further comprising: checking a floor of the system for an object with a light carpet module; and stopping operation of a motor of an associated storage unit when an object is detected in the path of the associate storage unit by the light carpet module. 